Title: LiteSpeed Cache Image Optimisation – failed to decode post json
Last modified: April 8, 2020

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# LiteSpeed Cache Image Optimisation – failed to decode post json

 *  Resolved [devisionuk](https://wordpress.org/support/users/devisionuk/)
 * (@devisionuk)
 * [6 years, 2 months ago](https://wordpress.org/support/topic/litespeed-cache-image-optimisation-failed-to-decode-post-json/)
 * Hi,
 * Recently installed LiteSpeed Web Server and subsequently installed LiteSpeed 
   Cache plugins on all relevant WordPress installations via WHM admin > LiteSpeed
   Web Server.
 * I’m having a problem with Image Optimisation on one of the sites. The output 
   log for the issue starts with this error:
 * `[IAPI] failed to decode post json: "hash does not match: ClientCB`
 * followed by a chunk of HTML code outputting this error:
 * `Sorry, there was an error. Please be sure JavaScript and Cookies are enabled
   in your browser and try again`
 * The full section of the output log error is
 *     ```
       04/08/20 01:02:18.804 [82.71.48.123:59617 1 TyK] [IAPI] failed to decode post json: "hash does not match: ClientCB
       04/08/20 01:02:18.832 [82.71.48.123:59617 1 TyK] [IAPI] request key failed: 
       04/08/20 01:02:18.836 [82.71.48.123:59617 1 TyK] [IAPI] posting to : https://eu.wp.api.litespeedtech.com/media_sync_data
       04/08/20 01:02:18.876 [82.71.48.123:59617 1 TyK] [IAPI] failed to decode post json: "no auth_key"
       04/08/20 01:02:18.885 [82.71.48.123:59617 1 TyK] [Ctrl] 301 from https://www.gbstampline.com/wp-admin/admin.php
       04/08/20 01:02:18.885 [82.71.48.123:59617 1 TyK] [Ctrl] 301 to https://www.gbstampline.com/wp-admin/admin.php?page=lscache-optimization&type=sync_data
       04/08/20 01:02:18.885 [82.71.48.123:59617 1 TyK] [Ctrl] X Cache_control -> no Cache ( 301 to same url )
       04/08/20 01:02:18.886 [82.71.48.123:59617 1 TyK] [Ctrl] not cacheable before ctrl finalize
       04/08/20 01:02:18.886 [82.71.48.123:59617 1 TyK] [Router] get_uid: 1106
       04/08/20 01:02:18.886 [82.71.48.123:59617 1 TyK] [Router] get_role: administrator
       04/08/20 01:02:18.887 [82.71.48.123:59617 1 TyK] X-LiteSpeed-Cache-Control: no-cache
       04/08/20 01:02:18.887 [82.71.48.123:59617 1 TyK] [Optm] bypass: Not frontend HTML type
       04/08/20 01:02:18.887 [82.71.48.123:59617 1 TyK] End response
       ```
   
 * I get the same ‘failed to decode json’ error when trying to send the report to
   LiteSpeed
 * Report number: WXSHLWHJ
    Report date: 04/08/2020 14:19:01

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Support [qtwrk](https://wordpress.org/support/users/qtwrk/)
 * (@qtwrk)
 * [6 years, 2 months ago](https://wordpress.org/support/topic/litespeed-cache-image-optimisation-failed-to-decode-post-json/#post-12646769)
 * Hi,
 * This usually happens when you have some kind of protective plugins that checks
   incoming traffic which in this , image server callback are not exactly a “normal”
   browser request , so it got stopped and inspected ,therefore hit error
 * from the log message, whatever this plugin is , it requires javascript and cookie
   to perform the check.
 * Please try disable these kind of plugins or add our [IPs](http://wp.api.litespeedtech.com/ips)
   into its whitelist
 * Best regards,
 *  Thread Starter [devisionuk](https://wordpress.org/support/users/devisionuk/)
 * (@devisionuk)
 * [6 years, 2 months ago](https://wordpress.org/support/topic/litespeed-cache-image-optimisation-failed-to-decode-post-json/#post-12648261)
 * RESOLVED
 * I have resolved this issue. It appears that WP SpamShield was conflicting with
   the LiteSpeed Cache plugin.
    -  This reply was modified 6 years, 2 months ago by [devisionuk](https://wordpress.org/support/users/devisionuk/).
    -  This reply was modified 6 years, 2 months ago by [devisionuk](https://wordpress.org/support/users/devisionuk/).
 *  Plugin Support [qtwrk](https://wordpress.org/support/users/qtwrk/)
 * (@qtwrk)
 * [6 years, 2 months ago](https://wordpress.org/support/topic/litespeed-cache-image-optimisation-failed-to-decode-post-json/#post-12651762)
 * Glad to know you solved it 🙂

Viewing 3 replies - 1 through 3 (of 3 total)

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## Tags

 * [image optimisation](https://wordpress.org/support/topic-tag/image-optimisation/)
 * [resolved](https://wordpress.org/support/topic-tag/resolved/)

 * 3 replies
 * 2 participants
 * Last reply from: [qtwrk](https://wordpress.org/support/users/qtwrk/)
 * Last activity: [6 years, 2 months ago](https://wordpress.org/support/topic/litespeed-cache-image-optimisation-failed-to-decode-post-json/#post-12651762)
 * Status: resolved